Currently, batteries, for example, the Li-ion batteries, are widely used to provide power supply to varieties of battery-powered devices, such as notebook computers, electric vehicles (EVs), hybrid electric vehicles (HEVs) and power tools. A charging circuit is typically used to charge the battery. During a charging process, undesired conditions of the battery, such as over-voltage, under-voltage, over-current and over-temperature conditions, may shorten the battery life.
A protection apparatus can be employed to protect the battery. FIG. 1 shows a conventional protection apparatus 100. The protection apparatus 100 includes a detection block 120 and a protection enable block 180.
The status of each cell in the battery, such as cell voltage, cell current and cell temperature, can be monitored. A monitoring signal 101 is sent to the detection block 120. The detection block 120 checks the monitoring signal 101 to detect an undesired condition in the battery. When the undesired condition is detected, the detection block 120 sends an alert signal 152 to the protection enable block 180. The protection enable block 180 can generate a triggering signal 158 to burn a fuse and thus the battery can be disconnected from the charging circuit.
However, the robustness of the fuse may be deteriorated in the conventional protection apparatus 100. For example, an undesired condition which may be caused by the voltage glitches can be detected by the detection block 120. The triggering signal 158 is generated to burn the fuse. Before the fuse is completely burnt, the undesired condition may be recovered and thus the protection process can be suddenly suspended. Consequently, the robustness of the fuse may be deteriorated due to frequent starting and suspending of the protection process. Thus, the fuse may need to be replaced frequently.